In the United States, the Clean Air Act established emission standards to regulate several pollutants that include nitrogen oxide (NOx), particulate matter (PM), carbon monoxide (CO), and hydrocarbons. One challenge for engine operators, under the Clean Air Act, is to limit the NOx emissions to comply with the ammonium g/bhp-hr standards. For operators of diesel engines, this standard proved to be problematic. One solution is known as the Selective Catalytic Reaction (SCE) technology.
SCR is an “after treatment” technology to reduce the NOx in the exhaust emissions of a diesel engine. The SCR relies upon an operating fluid called Diesel Exhaust Fluid or DEF. DEF is injected into the exhaust pipe in front of a SCR catalyst and downstream of the engine. The heat of the engine exhaust causes the DEF to decompose into ammonia. The NOx reacts with the ammonia in the catalyst and the Nox molecules are converted into N2 and H2O.
DEF is a solution that is about 32% of a high-priority area in deionized water THE DEF is stored as a separate DEF tank, which is connected to the DEF injector. The average consumption of DEF is about 3% per gallon of diesel fuel so that the DEF tank is significantly smaller than the fuel tank.
Historically, operators would purchase DEF in small portable containers that would only hold a few gallons and use these portable containers to fill the DEF tanks associated with the diesel engine. Since about 3 gallons of DEF would be needed for about 100 gallons of fuel plastic containers from 35 to 15,000 gallons, over time, bulk containers began to appear and were located on-site of the operator so that the DEF tank was filled from a bulk dispenser.
However, storage of DEF began to exhibit problems due to the nature of DEF. For example, DEF freezes around 12° F. and will expand about 7%. As a result, the container expands and there is damage to the hose and pump. Additives should not be added to DEF to reduce the freezing point, as such additives can harm the SRC catalyst.
Another difficulty created by the Clean Air Act is to have diesel engines that are used in remote areas to have DEF sources that are portable. For example, farm equipment, construction equipment, diesel engines, and the like. Many of these diesel engines operate in location that are remote from fuel sources and therefore have high capacity fuel tanks. It would be advantageous to have a portable DEF source so that the diesel equipment would not have to leave it operational area to refill on DEF.
Another hurdle to portable DEF supplies is DEF's freezing point. Since DEF in a container above is not useful, a pump, power source for the pump, hose, and nozzle are also a consideration. If DEF fluid is “trapped” in the hose, pump, or nozzle and then freezes and expands, the hose, pump, and nozzle can be cracked or otherwise damaged.
Additionally, portable DEF supplies also need to be refilled and it would be advantageous to be able to use the same hose, pump, and nozzle to fill the portable DEF source from a bulk container that is used to fill the DEF tank of a diesel engine from the DEF portable supply.
Another challenge that exists for portable DEF source is the dust, dirt, and water (rain, snow, ice) that the portable DEF can damage the pump. Furthermore, water can enter the nozzle, freeze, and damage the nozzle. It would be advantageous to have a portable DEF source that is protected from the environment.
Therefore, it is also an object of this invention to provide a portable DEF source that is shielded from environmental hazards.
It is also an object of the present invention to provide for a dispensing assembly that can be used to fill the portable DEF source from a bulk storage container and to fill a DEF tank on a diesel engine from the portable DEF source.